Method of drying gases



July 31, 1923- 11,463,279.

E. H. ARNOLD ET AL METHOD OF DRYING GASES Filed Nov. 9. 1921 K ATTORNEY EDWIN H. ARNOLD, or COVENTRY, AND WILLIAM 'r. WAKEFORD, OnPnovIDENcE.

RHODE ISLAND, ASSIGNORS TO THE NITROGEN CORPORATION, or PROVIDENCE RHODE ISLAND, A CORPORATION OF RHODE IsLAND.

METHOD OF DRYING GASES.

Application filed November" To all who-mit may ooa wem:

Be it known that we, EDWIN H. ARNOLD and \VILLIAM T. 'WAKEFORD, citizens of the United States, residing at Coventry and Providence, in the counties of Kent and Providence, respectively, and State of Rhode Island, have invented certain new and useful Improvements in Methods of Drying Gases, of which the following is a specification.

This invention relates to an improved method and apparatus for drying gases and is particularly adapted for usein drying gases under low pressure, such for example as nitrogen and hydrogen used in the synthesis of ammonia from its elements.

One object of the invention is to provide an improved method of drying gases whereby the operation can be efliciently conducted at comparatively low pressure and by means of relatively simple and inexpensive apparatus without danger of loss of the gases being dried or their contamination by the air.

Another object of the invention is to provide a simple and efficient apparatus for drying gases, the parts of which are so constructed and arranged as to permit the same to be employed for drying gases, and enable the gases to be dried to readily contact at all times with the drying material and at the same time prevent loss of the gases or the cessation of the operation to remove spent drying material.

' Other objects and advantages of the invention relate to certain details of construction and methods of operation as will be more fully set forth in the detailed description to follow.

Referring to the drawings:

Fig. 1 is a side elevational view of the structure, portions of which are broken away to show the arrangement of the parts, and.

Fig. 2 is a horizontal sectional view, taken along the line 2-2 of Fig. 1.

In the embodiment of the invention illustrated herewith 1 designates a casing which may be constructed of any suitable material, and which comprises an upper substantially cylindrical portion 2 and a lower reduced portion 3. The casing is shown herewith as being of integral construction although it may be formed of sections arranged in any desired manner, provided that the sections are so jointed together as to prevent the es- 9, 1921. Serial No. 514,087.

cape of the gases through the connected portrons thereof; The casing is preferably divided into separate chambers 4 and 5 by means of a plate 6 which is supported in the present instance by an annular ring 7 of angular form suitably secured to the casing although any other suitable means may be employed for supporting the plate 6 which maybe found expedient. The plate 6 is provided with a plurality of perforations 8 formed therein, the size and shape of which may be variedas desired depending upon the drying material employed and the conditions of Operation. An inlet pipe 9 is led into the chamber 5 at any suitable point and serves as an inlet through which the gases to be drled are conducted into the chamber 5, while an outlet pipe 10 leads from the top of the chamber 4 through which the gases may pass after they have passed upwardly from the chamber 5 into the chamber 4 through the Open1ngs8 in the plate 6 and contacted with the drying material 11 contained in the chamber 4.

An airtight-closure 12 of any suitable constructlon is provided for the chamber 4 through which the drying material may be placed in the chamber.

A shaft 14 is rotatably mounted in the plate 6 substantially centrally thereof and may be supported either by the plate 6 or by a bearing member 15 suitably secured to the interior wall of the casing. The shaft 14 is provided with an angular portion 16 adjacent to the upper end thereof which fits within an angular opening formed in a hub 17 from which radiate a plurality of stirrer arms 18, the hub being held against accidental removal from the shaft by means of a nut 19. The arms 18 are curved slightly throughout the major portion of their exto prevent undue longitudinal movement of tent and are each provided with a sharpened the shaft 2a in its bearings. The shaft 24: extends through the side of the casing and ha secured thereto a wheel provided with a handle 31 whereby the shaft may be readily rotated from without the casing and the stirrer actuated to agitate the drying material and cause the spent portions thereof to till (ill

pass through the openings 8 in the plate 6 and into the chamber 5 The lower portion of the casing at the base of the chamberio is formed with a semitubular portion 32 in which is mounted a feed screw 33 carried by a shaft 34 mounted in a bearing formed in one wall of the casing and in a plate 35 carried by the opposite side of the casing, said shaft being provided with a crank 36 secured to the end thereof outwardly of the casing whereby the feed screw may be rotated; A spout 37 projects outwardly from the semi-tubular portion 33 at the end of the feed screw whereby the spent material 38 in the lower portion of thecharnber 5 may be forced by the feed screw through an opening 39, formed in the wall of the casing and thus pass into any suitable receptacleplaced beneath the spout. A flaring shield 40 may be formed integral with or suitably secured to the bearing member later extending over the pinion 22 and screw 23 to prevent the spent material passing throu h the openings in the plate 6 from becomingTodged between the screw and pinion and preventing the proper operation of the same.

Suitable standards a l support the casing l a suitable distance from the floor to permit the placing of a receptacle beneath the spout 37 for receiving the spent material therefrom. A. window 42 of glass or other transparent material may be located in one side of the wall of the chamber 5 whereby the operator can readily determine the height of the spent material in the chamber and thus be apprised of the necessity of removing a portion of the same by rotating the feed screw 33 and if desired, one or more similar windows may be inserted in that portion of the casing surrounding the charm, her 4- whereby the amount of spent material present may be readily determined and thus apprise the operator of the necessity for actuating the stirrer to remove the same to the chamber 5.

The pipes 9 and 19 as well as the shafts 2t and 3d are provided with suitable supporting plates at the points where they enter the casing, and, if desired packing may be introduced between such plates and the wall or the casing to prevent loss or the gases at these points or access of air to the interior of the casing.

lln the drying of gases by means of the. apparatus above described drying material ll, which may be unslaclred lime, is intro due ed into the chamber a through the open-- neeaare ing lZ, The lime in. its unslacked condition being in lumps of substantial size is supported by the plate 3. The cover 12 being replaced the gases to be dried are introduced through the ipe 9 into the chamber 5 and pass upward y through the openings 8 in the plate 6, it being understood that a suflicient quantity of the spent material 38 is constantly retained in the chamber 5 to act as a gas seal both for preventing the escape of the gases to be dried as well as to prevent the access or air to the interior of the casing. The gases are introduced into the casing under comparatively low pressure such, for example, as from two to five pounds per square inch, although it is to be understood that the apparatus is in no sense limited to use for drying gases at the pressures mentioned but may be employed at higher or lower pressures depending upon the conditions under which the work is to be carried out and the care exercised in constructing and operating the apparatus to prevent loss ofthe gases. As the gases to be dried pass upwardly through the openings in the plate 6 into contact with the drying material the moisture contained in the gases is absorbed by the material and, when lime is employed as a drier, the lumps break down into a powdery form. Upon continued passage of the gases the powdery spent material tends to accumulate just above the plate 6 and thus renders it increasingly diflicult for the gases to penetrate the same. Accordingly at suitable intervals the wheel 30 is rotated to actuate the stirrer through the gearing previously described and the arms 18 passing through the powdery spent material agitate the thus causing the same to pass through the openings in the plate 6 and fall into the chamber 5, whereby the spent material is removed from the chamber t and the passage of the gases through the active drying material facilitated. As previously stated, a certain amount of spent material. 38 is always retained in the chamher 5 to act as a seal. The quantity present may be observed through the window 42 and whenever an excessive amount is present the cranlr 36 may be rotated whereby a portion thereof is forced out through the opening 39 into a suitable receptacle.

From the above description it will be seen that we have provided a simple and eficient form of apparatus for drying gases whereby gases may be dried under comparatively low pressure and without undue loss of the same by reason or" leakage or contamination the same by access or air thereto. The casing being substantially gas tight through out its extent, except for the opening 39 which is protected by the material 33, the gases pass therethrough without loss and continuous op r there drying material in the chamlltl ation be had so long as ber 4, without Stopping the operation to open the casing and remove spent material, thus effecting substantial economies of operation.

Having described our invention, what we claim is:

1. The method of drying gases which comprises, passing the gases under low pressure into a chamber provided with a perforated wall and then upwardly through said perforated wall and into a second chamber where the said gases pass into contact with drying material contained in said, second chamber, contamination of said gases by contact with the air while in said chambers bein prevented by maintaining a constant supp y of said drying materlal in comminuted form in said first named chamber.

2. The process of drying gases which comprises, the bringing of the gases to be dried into contact with drying material within a casing, the particles of which material break down upon absorption of moisture to form a powdery mass, the removal of the powdery residue to facilitate the passage of the gases through the drying material, and the use of said powderymaterial thus removed in con- 'unction with .said casing to form a seal whereby the escape of the gases to be dried is prevented.

3. The process of drying gases WhlCl'l comprises, continuously passing gases to be dried into contact with drying material the parti- ,eles of which materia break down upon absorption of moisture to form a powdery mass, and the removal of the powdery residue from the chamber containing the drying material without interrupting the passage of gases to be dried through the drying material. v y

4. The process of dyring gases which comrises continuously passing gases into contact with drying material which breaks down upon absorption of moisture into a powdery mass and the removal of the powdery residue gases with drying material supported by said plate,

causing some of said drying material in reduced form to fall through the perforations in said plate into the base of said container, and maintaining a quantity of said drying material in the base of said container to serve as a closure for the opening therein and thus preventing contamination of said gases by contact with the air.

6. The process of drying gases which comprises, paming the gases into contact with from the chamber containing. the drying material while excluding a1r drying material adapted to disintegrate upon absorption of moisture from said gases, said drying material being positioned in a container from which the external atmosphere is excluded and which is provided with an opening in the base thereof for the removal of said drying material after the same has become converted into powdered form by the absorption of moisture from said gases, converting a portion of the drying material into finely powdered form by contact of the gases therewith, collecting said powdery drying material in the base of said container, removing a portion of said powdery drying material from the base of said container, and maintaining a quantity of said powdery dryin material in the base of said container at all times to exclude air therefrom during the passage of gases therethrough.

7. The process of drying gases which comprises, passing the gases under low pressure, into a chamber provided with a perforated wall and then upwardly through said perforated wall and into a second chamber, contacting said gases with drying material in lump form contained in said second chamber to absorb moisture from said gases and effect a disintegration of said drying ma- I terial to form a powdery mass, effecting the removal of said powdery mass from said second chamber to said first chamber to expose fresh drying material for contact with said gases, and excluding atmospheric air from both of said chambers during the passage of said gases therethrough.

8. The process of drying gases which comprises, passing the gases through a body of drying material in lump form to absorb moisture from the gases and effect disintegration of said drying material to form a powdery mass relatively impervious to the passage of gases therethrou h, effecting the removal of the, powdery rying material from the pathof the gases to be dried, and constantly maintainin a supply of said powdery drying material in position to exclude air from the gases to be dried 9. In a process for drying gases, the steps comprising,'continuously passing the gases to be dried into contact with drying material in lump form to remove moisture therefrom and convert the said drying material into a powdery mass, removing said powdery mass from the path of the gases to expose fresh drying material to the gases and eml' ll ploying the powdery material to exclude atsupported in said receptacle above the base thereof, to absorb moisture from the gases and efi'ect disintegration of said drying material and convert said drying material into a powdery material relatively impervious to the passage of gases therethrough; efiec-ting the removal of the powdery material from the path of the gases to be dried to the base of said receptacle, removing a portion of the powdery material from the base of said receptacle, and maintaining at all times a quantity of said powdery material in the base of said receptacle to prevent the escape of the gases to be dried as Well as the contamination of said gases by atmospheric air.

11. The process of drying gases which comprises, passing the gases to be dried into contact with drying material in lump form to absorb moisture from said gases and effect disintegration of said drying material to form therefrom a powdery material relatively impervious to the passage of gases therethrough, and utilizing said powdery material to exclude air from the gases to he dried.

In testimony whereof We have atfixed our signatures,

Enema n. ARNULD. rnnran r, Waterman, 

